Controller, data storage device, and data communication system having variable communication speed

ABSTRACT

A main controller for use within a data storage device including a first data storage device and a second data storage device is disclosed. The controller includes a memory configured to store a plurality of protocol program data, and a processor configured to receive a host control signal from a host defining a primary operation, and to execute protocol program data selected from the plurality of protocol program data to define a first data communication protocol in accordance with the received host control signal. The processor is further configured to electrically store data in the first data storage device or magnetically store the data in the second data storage device during a secondary operation associated with the first operation, wherein the data is communicated from the processor to the first data storage device or the second data storage device during the secondary operation using a second.

PRIORITY STATEMENT

This application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2008-0068992 filed on Jul. 16, 2008, the subject matter of which is hereby incorporated by reference.

BACKGROUND

The present invention relates to a data communication technology, and more particularly, to a controller capable of adaptively adjusting the speed or data rate of communication. Embodiments of the invention include controllers capable of adjusting communication speed, data storage devices including such a controller, and data communication systems including such a data storage device.

The hard disk drive (HDD) is a conventional, magnetic storage device that is highly competitive on a price per stored data basis. The HDD is capable of storing a large volume of data, but data access (read/write) speeds are not exceptional. However, due to low manufacturing costs, HDDs are widely used as bulk data storage units.

The HDD generally reads/writes data from/to a rotating magnetic disk (or recording medium) using a mechanical read/write head. The mechanical nature of the read/write head and its constituent movable components suffer from such problems as a vibration, noise, heat build-up and the resulting operating distortion, mode-specific disturbance issues, complexity of manufacture, and increasing cost as size constraints become more severe. HDDs also require a relatively long time to retrieve stored data, as the disk must be mechanically rotated to the sector storing the requested data and the read/write head must be moved over the sector. Increasing the data access speed of HDDs requires faster operating speeds for disk rotation and read/write head movement. Unfortunately, such increases tend to consume more power and aggravate some of the foregoing problems, such as noise and heat.

Particularly in the context of small, portable, electronic host devices, a data storage device is required that provides better data access speeds with reduced power consumption.

SUMMARY

In one aspect of the inventive concept, a main controller for use within a data storage device including a first data storage device and a second data storage device is disclosed. The controller comprises; a memory configured to store a plurality of protocol program data, and a processor configured to receive a host control signal from a host defining a primary operation, and execute protocol program data selected from the plurality of protocol program data to define a first data communication protocol in accordance with the received host control signal, wherein the processor is further configured to electrically store data in the first data storage device or magnetically store the data in the second data storage device during a secondary operation associated with the first operation, wherein the data is communicated from the processor to the first data storage device or the second data storage device during the secondary operation using a second data communication protocol different from the first data communication protocol.

In another aspect of the inventive concept, a data storage device is disclosed and comprises; a first controller configured to electrically access data from a first data storage device, a second controller configured to magnetically access data from a second data storage device, and a main controller configured to receive a host control signal from a host using a first data communication protocol selected from the plurality of data communication protocols, and either (1) cause data to be electrically stored in the first data storage device or (2) cause the data to be magnetically stored in the second data storage device using a second data communication protocol different from the first data communication protocol.

In another aspect of the inventive concept, a data communication system is disclosed and comprises; a host and a data storage device communicating via a first data communication protocol, wherein the data storage device comprises; a first controller configured to electrically access data from a first data storage device, a second controller configured to magnetically access data from a second data storage device, and a main controller configured to receive a host control signal from the host using the first data communication protocol, and either (1) cause data to be electrically stored in the first data storage device or (2) cause the data to be magnetically stored in the second data storage device using a second data communication protocol different from the first data communication protocol.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the present inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic block diagram of a data transmission system including a data storage device according to an embodiment of the invention;

FIG. 2 is a flow chart summarizing a method of varying the communication speed of a data communication system including a main controller according to an embodiment of the invention; and

FIG. 3 is a flowchart summarizing a method of varying the communication speed of a data communication system including a main controller according to another embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to certain embodiments of the inventive concept, examples of which are illustrated in the accompanying drawings. Throughout the written description and drawings like reference numerals refer to the like or similar elements.

FIG. 1 is a schematic block diagram of data communication system 10 including a data storage device 30 according to an embodiment of the invention. The data communication system 100 may be a computer system, a terminal device system, or an input/output device system. The data communication system 10 may be included within any type of consumer equipment (CE), (e.g., a HDD recorder, personal portable terminal such as a cellular phone and PDA, PC computer, laptop computer, desktop computer, navigator device, home automation system, MP3 music player, camcorder, video player, storage server, portable multimedia player (PMP), etc.). Data communication system 10 generally comprises a host 20 (e.g., a host controller, I/O controller, microprocessor, CPU, chip-set, etc.) and data storage device 30 designed and operated in accordance with an embodiment of the invention.

In the illustrated embodiment of FIG. 1, data communication system 10 is assumed to operate according to a serial data communication protocol, such as the conventionally understood Serial ATA (SATA) interface specification. That is, serial data is exchanged between host 20 and data storage device 30 according to one or more conventional protocols controlled by host 20. The SATA protocol is merely one example that will be used to describe the illustrated embodiment. For example, the SATA protocol generally provides SATA Gen1 and SATA Gen 2 data communications capabilities allowing the exchange of serial data at (e.g.,) 1.5 Gbps and 3.0 Gbps, respectively.

Under these working assumptions, the SATA Gen1 may result in performance problems given its relatively slow data communication capabilities between host 20 and a main controller 40 within data storage device 30. Nonetheless, SATA Gen1 runs with low power consumption and is desirable over SATA Gen2 where data communication demands do not exceed its capabilities. On the other hand, the SATA Gen2 offers much faster data communication capabilities between host 20 and main controller 40, but does so at higher power consumption than SATA Gen 1. Ideally, the lower speed, lower power consumption protocol (e.g., SATA Gen1) will be used whenever practicable, and the higher speed, higher power consumption protocol will be used only as needed to provide high demand data communication between host 20 and data storage device 30.

Data storage device 30 includes a first (higher throughput) data storage device 55 (e.g., an SDD), a second (lower throughput) data storage device 65 (e.g., an HDD), a first controller 57 controlling the operation of the first storage device 55, a second controller 67 controlling the operation of the second data storage device 65, a system bus 50, and main controller 40. Main controller 40 controls the overall data communication, including the protocol-in-use and/or speed of data communication. Main controller 40 thus generates a plurality of control signals that define the operation of the first controller 57 and the second controller 67. Payload data and related command, control and address signals are communicated between the first controller 57 and second controller 67 via system bus 50. In one more specific embodiment of the invention, the first data storage device 55 and the first controller 57 may be embodied on a single integrated circuit chip and/or second data storage device 65 and the second controller 67 may be embodied on a separate integrated circuit chip.

According to one embodiment of the invention, the first data storage device 55, the second storage device 65, the first controller 57, and the second controller 67 may be implemented is a so-called hybrid HDD, wherein the main controller 40 serves as a storage controller or a bridge chip within the hybrid HDD.

The first data storage device 55 may be implemented in one or more non-volatile memory device(s) such as a programmable read only memory (PROM), an erasable programmable read only memory (EPROM), an electrically erasable programmable read only memory (EEPROM), a flash memory, a ferroelectrics random access memory (FRAM), a magnetic random access memory (MRAM), a phase change random access memory (PRAM), a nano random access memory (NRAM), a silicon-oxide-nitride-oxide-silicon (SONOS), or racetrack memory. In one embodiment of the invention, the first data storage device 55 is implemented in non-volatile memory as a so-called Solid State Drive/disc (SSD). As is conventionally understood, the SDD is an excellent device for storing frequently accessed data, such as operating system programming.

The second data storage device 65 may be implemented as a magnetic storage device, such as a HDD. This type of implementation allows bulk data or payload data less frequently accessed to be stored magnetically at the low costs associated with HDDs. Such bulk data may include text files, video files, and/or an image files.

The main controller 40 communicates with first controller 57, second controller 67, and host 20. In the illustrated embodiment, main controller 40 includes a memory 45 storing protocol program data. The term “protocol program data” is used to denote certain data controlling at least the communication (i.e., transmission and receipt) speed for data being exchanged between a main controller processor 43 and at least one of first controller 57, second controller 67, and host 20. That is, the processor 43 is capable of executing the protocol program data to define one or more data protocols used by main controller 40.

The protocol program data executed by processor 43 may be selected from a group of protocol program data stored in memory 45 as indicated by control signal(s) received from host 20. A default protocol program data may be executed upon initial start-up of the data storage device 30. This default protocol program data will define a first data communication speed at which the initial control signals from host device 30 are received. The processor 43 analyzes the received host control signals, and may thereafter adjust the data transmission speed in accordance with protocol program data stored in memory 45 in response to the host control signals. For example, a second data communication speed faster than the first data communication sped may be selected in relation to data being stored in the first data storage device 55 and/or the second data storage device 65.

FIG. 2 is a flowchart summarizing a method of varying the data communication speed within a communication system including a main controller according to an embodiment of the invention. It is assumed that host 20 initially communicates with main controller 40 using the SATA Gen1 protocol (e.g., as a default or start-up protocol). Hence, main controller 40 initially receives the host control signal from host 20 at a first communication speed, (e.g., 1.5 Gbps) (S100). The host control signal received from host 20 may take many forms and may be associated with an access operation (e.g., a read command or write command). The host control signal may include payload data, overhead data, error correction coding, address information, and/or control information, etc.

It is now further assumed that as part of the received host control signal, main controller 40 now retrieves and executes protocol program data stored in memory 45 that enables processor 43 to implement a second (higher) data communication speed (e.g., SATA Gen2 or one of a plurality of transmission speeds that may be set at 1.5*(2^(n-1))Gbps, where “n” is a natural number. (S120). Memory 45 may store any reasonable number of protocol program data, each respectively defining a data transmission speed, data transmission parameters, an error correction code type, etc.

Using the second data communication protocol running at the second data communication speed (e.g., 3.0 Gps), as indicated by the host control signal, main controller 40 may communicate payload data to first data storage device 55 or second storage device 65. In the working example, the second higher data communication speed is more typically used to communicate frequently accessed data between the first data storage device 55 and processor 43 via data bus 50. In contrast, when the host control signal indicates a requirement to store bulk data in the second data storage device 65, the first data communication protocol running at the first (slower) data communication speed (e.g., 1.5 Gps) may be used.

In this manner, various data operations (e.g., read, write, program, erase, verify, etc.) may be performed by data storage device 30 in relation (i.e., in view of) to the nature of the data to be stored and the actual type of data storage device to be used in the storage process. The main controller 40 may communicate with at least one of first controller 57, which controls operations of a first data storage device 55, and second controller 67 for controlling operations of a second data storage device 65 (S120). In the foregoing, the communication protocol and resulting data communication speed between the main controller 40 and host 20 may be different from the data communication protocol and the resulting data communication speed between the main controller 40 and either one or both of controllers 57 and 67.

That is, main controller 40 may perform “primary operation” with the host 20 based on the content of a host control signal using a first data communication protocol selected from a group of possible data communication protocols. However, execution of the primary operation may require one or more “secondary operations” between the main controller 40 and one or both controllers 57, 67. Such secondary data access operation(s) may be performed at an entirely different data communication speed using different protocol program data. For example, main controller 40 may access first data storage device 55 by communicating with first controller 57 via system bus 50 at 3.0 Gbps, and may access second data storage device 65 by communicating with second controller 67 via system bus 50 at 1.5 Gbps.

For convenience of explanation in the foregoing example, it has been assumed that host 20 communicates with main controller 40 using a conventionally defined SATA interface specification, selected from SATA Gen1, SATA Gen2, SATA Gen3, etc. However, while host 20 may mandate that main controller 40 use a SATA interface specification during a primary operation, main controller 40 may perform one or more secondary operations using a completely different (i.e., non-SATA interface specification) type of data communication protocol. Further, while the emphasis in the foregoing examples has been placed on communication speed, any other type of data communication protocol parameter may be additionally or alternately varied.

FIG. 3 is a flowchart summarizing a method for varying the communication speed within a data communication system including a main controller according to an embodiment of the invention.

First, host 20 is assumed to communicate with main controller 40 using a first data communication protocol (e.g., SATA Gen1), such that main controller 40 receives a host control signal at a first communication speed, (e.g., 1.5 Gbps) (S130). The host control signal defines a primary operation (e.g., a read/write operation) to be executed between host 20 and data storage device 30. Thus, the host control signal may include payload data, address data, command or control information, etc.

In this regard, main controller 40 executes first protocol program data stored in memory 45 that corresponds with the first data communication protocol in order to receive the host control signal. It is assumed that the host control signal received by main controller 40 mandates the use of a second data communication protocol establishing a second data communication speed (e.g., 3.0 Gps), different from the first data communication speed (S140). In response to the received host control signal and at the established second data communication speed, main control 40 now communicates with one of first controller 57 or second controller 67 (S150). In the illustrated example, it is further assumed that the second data communication speed is faster than the first and that the processor 43 stores frequently accessed data (i.e., program code implementing OS routines) in first data storage device 55. The actual transfer and storage of the OS program code from main controller 40 and first data storage device 55 via system bus 50 and first controller 57 is a secondary operation executed by main controller 40 in response to the primary operation indicated by the host control signal received from host 20.

Subsequent to the execution of the foregoing primary operation, the main controller 40 receives a next host control signal indicating another primary operation. In similar vein, the next host control signal is analyzed upon receipt (S160).

Main controller 40 is currently operating in accordance with a defined data communication protocol. This data communication protocol may or may not be appropriate to the execution of the next primary operation or a corresponding next secondary operation. Accordingly, the current data communication protocol running on main controller 40 must be evaluated in relation to the next host control signal and its constituent data (S170).

If the current data communication protocol (and corresponding data communication speed) is appropriate, the current data communication protocol is maintained (S180), and main controller 40 will communicate with the first controller 57 or second controller 67 using the maintained data communication protocol (S190). For example, assuming the first primary operation stored (i.e., programmed) OS program data to the first data storage device 55 using the second data communication protocol running at the higher second data communication speed, the next primary operation might store (i.e., program) additional OS patch data to the first data storage device 55. In such a sequence, the second data communication speed established in (S140) is merely maintained, as between the first and next primary operations and their constituent secondary operations programming data to the first date storage device 55.

However, if the current data communication protocol (and corresponding data communication speed) is not appropriate, the current data communication protocol must be set (S210). To set a new data communication protocol according to the next host control signal, main controller 40 may access memory 45 to obtain corresponding protocol program data. In certain instances, host 20 may request a data communication protocol outside the set of data communication protocols enabled with the data storage device 30. In such circumstances, an appropriate indication may be returned to host 20 from processor 43, and host 20 may request another data communication protocol and corresponding speed (S220). Once a new data communication protocol has been selected, main controller 40 may communicate data implicated in the next host control signal to/from the first or second data storage device 55, 65 via system bus 50 and respective first and second controller 57, 67 (S230).

For example, after storing the OS program data in a first primary operation, the host may request storage of bulk file data to the second data storage device 65. This download of bulk data may be run at a lower speed since access download times associated with the second data storage device 65 are considerably less than the access download times for the first data storage device 55. Thus, “setting” a new data communication protocol may vary the resulting data communication speed up or down according to the received host control signal and its constituent data.

Main controller 40 may also monitor the state of system bus 50 and generate one or more control signals in accordance with this monitoring function. The data communication protocol associated with a secondary operation between main controller 40 and one or both of first and second controllers 57 and 67 may be selected (or set) in view of the system bus state, and/or the inflow of data from host 30. For example, if the system bus monitoring function indicates that system bus 50 is idle (or busy), main controller 40 may adjust the current data communication protocol accordingly.

As described above, data communication system 10 according to an embodiment of the invention may perform data communication between main controller 40 and first controller 57 and/or second controller 67 at a different data communication speed and using a different data communication protocol during a secondary operation than is used during a primary operation. The selection of an appropriate data communication protocol may take into account host operating conditions, user option selections, etc. This capability allows enhanced device compatibility between data storage device 30 and numerous hosts 20. Additionally, an improved balance between performance (e.g., data throughput speeds) and power consumption may be had.

Although several embodiments of the inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the scope of the appended claims and their equivalents. 

1. A main controller for use within a data storage device including a first data storage device and a second data storage device, the controller comprising: a memory configured to store a plurality of protocol program data; and a processor configured to receive a host control signal from a host defining a primary operation, and execute protocol program data selected from the plurality of protocol program data to define a first data communication protocol in accordance with the received host control signal, wherein the processor is further configured to electrically store data in the first data storage device or magnetically store the data in the second data storage device during a secondary operation associated with the primary operation, wherein the data is communicated from the processor to the first data storage device or the second data storage device during the secondary operation using a second data communication protocol different from the first data communication protocol.
 2. The main controller of claim 1, wherein the host control signal comprises at least one of payload data, address data, header data, command information, control information and error correction data.
 3. The main controller of claim 1, wherein the first data communication protocol defines a first data communication speed and the second data communication protocol defines a second data communication speed different from the first data communication speed.
 4. The main controller of claim 3, wherein the first and second data communication protocols are selected from a group of serial ATA (SATA) interface specifications.
 5. The main controller of claim 1, wherein the first data storage device is implemented with non-volatile memory, and the second data storage device is implemented with a magnetic disk.
 6. A data storage device comprising: a first controller configured to electrically access data from a first data storage device; a second controller configured to magnetically access data from a second data storage device; and a main controller configured to receive a host control signal from a host using a first data communication protocol selected from the plurality of data communication protocols, and either (1) cause data to be electrically stored in the first data storage device or (2) cause the data to be magnetically stored in the second data storage device using a second data communication protocol different from the first data communication protocol.
 7. The data storage device of claim 6, further comprising a system bus connecting the main controller with the first and second controllers.
 8. The data storage device of claim 6, wherein the first data storage device is implemented with non-volatile memory, and the second data storage device is implemented with a magnetic disk.
 9. The data storage device of claim 6, wherein the plurality of data communication protocols includes at least one serial ATA (SATA) interface specification.
 10. The data storage device of claim 6, wherein the main controller comprises: a memory configured to store a plurality of protocol program data respectively corresponding to the plurality of data communication protocols; and a processor configured to receive the host control signal and execute the first and second data communication protocols to define respectively a first data communication speed and a second data communication speed.
 11. A data communication system comprising: a host and a data storage device communicating via a first data communication protocol, wherein the data storage device comprises: a first controller configured to electrically access data from a first data storage device; a second controller configured to magnetically access data from a second data storage device; and a main controller configured to receive a host control signal from the host using the first data communication protocol, and either (1) cause data to be electrically stored in the first data storage device or (2) cause the data to be magnetically stored in the second data storage device using a second data communication protocol different from the first data communication protocol.
 12. The data communication system of claim 11, wherein the data storage device further comprises a system bus connecting the main controller with the first and second controllers.
 13. The data communication system of claim 11, wherein the first data storage device is implemented with non-volatile memory, and the second data storage device is implemented with a magnetic disk.
 14. The data communication system of claim 11, wherein the first and second data communication protocols are each respective serial ATA (SATA) interface specifications.
 15. The data communication system of claim 11, wherein the main controller comprises: a memory configured to store a plurality of protocol program data respectively corresponding to a plurality of data communication protocols including the first and second data communication protocols; and a processor configured to receive the host control signal and execute the first and second data communication protocols to define respectively a first data communication speed and a second data communication speed.
 16. The data communication system of claim 11, wherein the data communication system is consumer equipment. 